The invention relates to antennas, and more particularly to antennas utilized in a portable electronic device.
Antennas are utilized in various portable electronic devices, such as notebooks, for transmitting wireless signals. With reference to FIG. 1, U.S. Pat. No. 6,686,886 discloses antennas 501 and 502 utilized in a notebook. The antennas 501 and 502 are near a screen of the notebook and transmit wireless signals. The antennas 501 and 502 are oriented in different directions to improve transmission.
The antennas 501 and 502 are flat antennas. FIG. 2 shows the detailed structure of antennas 501 and 502, which comprise a first inverted L-shaped structure (composed of metal elements 702 and 703), a second inverted L-shaped structure (composed of metal elements 704 and 708), a cable 706 and a ground element 701. The first and second inverted L-shaped structures are coupled to the ground element 701. The cable 706 comprises a data line 705 and a ground line 707, the data line 705 is coupled to the metal element 703, and the ground line 707 is coupled to the ground element 701. The first and second inverted L-shaped structures each have two different resonant frequency transmitting wireless signals with two different frequency bands. Antennas 501 and 502, however, cannot transmit wireless signals in more than three different frequency bands, for example, signals comprising GSM900, DCS1800 and WLAN signals.